Claudia, a girl from New York, is just one month away from turning 12 and has decided to run away from home with her younger brother, Jamie. She knows she can't leave impulsively without a destination, so she plans everything perfectly, including their destination: the magnificent and grand Metropolitan Museum of Art.

When Claudia and Jamie settle into their new home, they become involved in a mysterious case surrounding an angel statue that was purchased by the museum at a premium price. Is it, perhaps, an unknown work by Michelangelo, worth millions? Claudia is determined to find out, and her mission leads her to the remarkable, secretive Mrs. Frankweiler, who sold the statue to the museum - and to some equally remarkable discoveries about herself.

Since its first publication nearly 50 years ago, the book "The Mixed-up Files of Mrs. Basil E. Frankweiler" has found a place in the hearts of generations of readers - and has become one of the most beloved children's books of all time.